630 research outputs found
Visualising software in cyberspace
The problems of maintaining software systems are well documented. The increasing size and complexity of modern software serves only to worsen matters. Software maintainers are typically confronted with very large and very complex software systems, of which they may have little or no prior knowledge. At this stage they will normally have some maintenance task to perform, though possibly little indication of where or how to start. They need to investigate and understand the software to some extent in order to begin maintenance. This understanding process is termed program comprehension. There are various theories on program comprehension, many of which put emphasis on the construction of a mental model of the software within the mind of the maintainor. These same theories hypothesise a number of techniques employed by the maintainer for the creation and revision of this mental model. Software visualisation attempts to provide tool support for generating, supplementing and verifying the maintainer’s mental model. The majority of software visualisations to date have concentrated on producing two dimensional representations and animations of various aspects of a software system. Very little work has been performed previously regarding the issues involved in visualising software within a virtual reality environment. This research represents a significant first step into this exciting field and offers insight into the problems posed by this new media. This thesis provides an identification of the possibilities afforded byU3D graphics for software visualisation and program comprehension. It begins by defining seven key areas of 3D software visualisation, followed by the definition of two terms, visualisation and representation. These two terms provide a conceptual division between a visualisation and the elements of which it is comprised. This division enables improved discussion of the properties of a 3D visualisation and particularly the idenfification of properties that are desirable for a successful visualisation. A number of such desirable properties are suggested for both visualisations and representations, providing support for the design and evaluation of a 3D software visualisation system. Also presented are a number of prototype visualisations, each providing a different approach to the visualisation of a software system. The prototypes help demonstrate the practicalities and feasibility of 3D software visualisation. Evaluation of these prototypes is performed using a variety of techniques, the results of which emphasise the fact that there is substantial potential for the application of 3D graphics and virtual reality to software visualisation
Storage free terrain simulation
Landscape visualisation is the process of recreating a natural environment and displaying it in an interactive graphical simulation. To do this a terrain is displayed together with accompanying plant life and other objects. Present landscape visualisation software is capable in theory of displaying very detailed and large landscapes. The software is also in theory capable of simulating environments with thousands if not millions of individually structured plants. In practice though, the simulation of such landscapes requires such a large amount of storage space that it is not achievable on personal computers. Even storing small landscapes with a moderate amount plant life can be a major development problem. The extent of this problem is such that modem simulators almost always exhibit the following limitations. • When detailed landscapes are stored to the hard disk, the area of terrain covered is usually very small. • When large terrains are stored to the hard disk the detail used is usually low. • When detailed plants are used in a landscape only twenty or so plants are created and used over and over again in the landscape. This work is an original approach to solving the storage space problem that involves not storing any landscape data to the hard disk at all. In this solution, instead of the landscape simulator displaying a landscape that is stored on a hard disk, the landscape simulator displays a landscape that is randomly generated. The landscape is produced on a need-to know basis, the only landscape that exists in the simulator is the landscape that the user of the simulator can see. If the user\u27s position in the landscape alters then the newly visible areas of landscape are created, and the areas no longer visible are removed from the simulator entirely. Areas of landscape being visited for a second time are always re-created the same way as they were originally created
Training of Crisis Mappers and Map Production from Multi-sensor Data: Vernazza Case Study (Cinque Terre National Park, Italy)
This aim of paper is to presents the development of a multidisciplinary project carried out by the cooperation between Politecnico di Torino and ITHACA (Information Technology for Humanitarian Assistance, Cooperation and Action). The goal of the project was the training in geospatial data acquiring and processing for students attending Architecture and Engineering Courses, in order to start up a team of "volunteer mappers". Indeed, the project is aimed to document the environmental and built heritage subject to disaster; the purpose is to improve the capabilities of the actors involved in the activities connected in geospatial data collection, integration and sharing. The proposed area for testing the training activities is the Cinque Terre National Park, registered in the World Heritage List since 1997. The area was affected by flood on the 25th of October 2011. According to other international experiences, the group is expected to be active after emergencies in order to upgrade maps, using data acquired by typical geomatic methods and techniques such as terrestrial and aerial Lidar, close-range and aerial photogrammetry, topographic and GNSS instruments etc.; or by non conventional systems and instruments such us UAV, mobile mapping etc. The ultimate goal is to implement a WebGIS platform to share all the data collected with local authorities and the Civil Protectio
Procedural modeling of plant ecosystems maximizing vegetation cover
Vegetation plays a major role in the realistic display of outdoor scenes. However, manual
plant placement can be tedious. For this reason this paper presents a new proposal in the field
of procedural modeling of natural scenes. This method creates plant ecosystems that maximizes the covered space by optimizing an objective function subject to a series of constraints
defined by a system of inequalities. This system includes the constraints of the environment
taking into account characteristics of the terrain and the plant species involved. Once the
inequality system has been defined, a solution will be obtained that tries to maximize the
radius of the projected area of the trees and therefore the extension of the vegetation cover
on the ground. The technique eliminates the trees that do not achieve a minimum growth
radius, simulating the typical competitive process of nature. Results show the good performance and the high visual quality of the ecosystems obtained by the proposed technique.
The use of this kind of optimization techniques could be used to solve other procedural
modeling problems in other fields of application.Funding for open access charge: CRUE-Universitat Jaume
Photorealistic visualisation of urban greening in a low-cost high- density housing settlement.
Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.Apartheid housing policies of the pre-1994 South African government, and the low-cost highdensity housing programmes of the post-1994 government, has given rise to numerous urban environmental problems, some of which could be addressed in a cost-effective and sustainable manner through urban greening, while simultaneously promoting biodiversity. Public participation in the planning of urban greening has been identified as being of vital importance, without which urban greening projects run a high, and expensive, risk of failure. Previous studies indicate that the greening priorities of residents in low-cost high-density housing settlements may differ considerably from those of managers and experts tasked with the protection and extension of the natural environment resource base. A system of participatory decision support is therefore required to reconcile the greening requirements of the community, and the ecological benefits of biodiversity. If language, literacy, map literacy and numeracy difficulties are to be avoided, and a sense of place or belonging is to be invoked, such a participatory decision support system should, ideally, be visually based, and capable of generating realistic eye-level depictions of the urban landscape. New computer-based landscape visualisation applications, which can directly utilise GIS, CAD and DEM data to produce detailed photo-realistic viewsheds, were deemed better suited to the task of visualising urban greening than existing GIS based mapping systems, CAD and traditional landscape visualisation methods. This dissertation examines the process of constructing a 3D computer model of the Mount Royal low-cost high-density housing settlement, situated in the eThekwini Municipality, KwaZulu-Natal, South Africa. Visualisations including terrain, natural features, indigenous vegetation, houses and roads were produced and submitted, with a questionnaire, to experts from different disciplines, Mount Royal residents and neighbors. Results from the expert survey indicate moderate support for visualisation in professional decision-making. However, both experts and residents expressed strong support for the accuracy and credibility ofthe visualisations, as well as for their potential in a participatory decision support system
Contributions to Big Geospatial Data Rendering and Visualisations
Current geographical information systems lack features and components which are commonly found within rendering and game engines. When combined with computer game technologies, a modern geographical information system capable of advanced rendering and data visualisations are achievable. We have investigated the combination of big geospatial data, and computer game engines for the creation of a modern geographical information system framework capable of visualising densely populated real-world scenes using advanced rendering algorithms. The pipeline imports raw geospatial data in the form of Ordnance Survey data which is provided by the UK government, LiDAR data provided by a private company, and the global open mapping project of OpenStreetMap. The data is combined to produce additional terrain data where data is missing from the high resolution data sources of LiDAR by utilising interpolated Ordnance Survey data. Where data is missing from LiDAR, the same interpolation techniques are also utilised. Once a high resolution terrain data set which is complete in regards to coverage, is generated, sub datasets can be extracted from the LiDAR using OSM boundary data as a perimeter. The boundaries of OSM represent buildings or assets. Data can then be extracted such as the heights of buildings. This data can then be used to update the OSM database. Using a novel adjacency matrix extraction technique, 3D model mesh objects can be generated using both LiDAR and OSM information. The generation of model mesh objects created from OSM data utilises procedural content generation techniques, enabling the generation of GIS based 3D real-world scenes. Although only LiDAR and Ordnance Survey for UK data is available, restricting the generation to the UK borders, using OSM alone, the system is able to procedurally generate any place within the world covered by OSM. In this research, to manage the large amounts of data, a novel scenegraph structure has been generated to spatially separate OSM data according to OS coordinates, splitting the UK into 1kilometer squared tiles, and categorising OSM assets such as buildings, highways, amenities. Once spatially organised, and categorised as an asset of importance, the novel scenegraph allows for data dispersal through an entire scene in real-time. The 3D real-world scenes visualised within the runtime simulator can be manipulated in four main aspects; • Viewing at any angle or location through the use of a 3D and 2D camera system. • Modifying the effects or effect parameters applied to the 3D model mesh objects to visualise user defined data by use of our novel algorithms and unique lighting data-structure effect file with accompanying material interface. • Procedurally generating animations which can be applied to the spatial parameters of objects, or the visual properties of objects. • Applying Indexed Array Shader Function and taking advantage of the novel big geospatial scenegraph structure to exploit better rendering techniques in the context of a modern Geographical Information System, which has not been done, to the best of our knowledge. Combined with a novel scenegraph structure layout, the user can view and manipulate real-world procedurally generated worlds with additional user generated content in a number of unique and unseen ways within the current geographical information system implementations. We evaluate multiple functionalities and aspects of the framework. We evaluate the performance of the system, measuring frame rates with multi sized maps by stress testing means, as well as evaluating the benefits of the novel scenegraph structure for categorising, separating, manoeuvring, and data dispersal. Uniform scaling by n2 of scenegraph nodes which contain no model mesh data, procedurally generated model data, and user generated model data. The experiment compared runtime parameters, and memory consumption. We have compared the technical features of the framework against that of real-world related commercial projects; Google Maps, OSM2World, OSM-3D, OSM-Buildings, OpenStreetMap, ArcGIS, Sustainability Assessment Visualisation and Enhancement (SAVE), and Autonomous Learning Agents for Decentralised Data and Information (ALLADIN). We conclude that when compared to related research, the framework produces data-sets relevant for visualising geospatial assets from the combination of real-world data-sets, capable of being used by a multitude of external game engines, applications, and geographical information systems. The ability to manipulate the production of said data-sets at pre-compile time aids processing speeds for runtime simulation. This ability is provided by the pre-processor. The added benefit is to allow users to manipulate the spatial and visual parameters in a number of varying ways with minimal domain knowledge. The features of creating procedural animations attached to each of the spatial parameters and visual shading parameters allow users to view and encode their own representations of scenes which are unavailable within all of the products stated. Each of the alternative projects have similar features, but none which allow full animation ability of all parameters of an asset; spatially or visually, or both. We also evaluated the framework on the implemented features; implementing the needed algorithms and novelties of the framework as problems arose in the development of the framework. Examples of this is the algorithm for combining the multiple terrain data-sets we have (Ordnance Survey terrain data and Light Detection and Ranging Digital Surface Model data and Digital Terrain Model data), and combining them in a justifiable way to produce maps with no missing data values for further analysis and visualisation. A majority of visualisations are rendered using an Indexed Array Shader Function effect file, structured to create a novel design to encapsulate common rendering effects found in commercial computer games, and apply them to the rendering of real-world assets for a modern geographical information system. Maps of various size, in both dimensions, polygonal density, asset counts, and memory consumption prove successful in relation to real-time rendering parameters i.e. the visualisation of maps do not create a bottleneck for processing. The visualised scenes allow users to view large dense environments which include terrain models within procedural and user generated buildings, highways, amenities, and boundaries. The use of a novel scenegraph structure allows for the fast iteration and search from user defined dynamic queries. The interaction with the framework is allowed through a novel Interactive Visualisation Interface. Utilising the interface, a user can apply procedurally generated animations to both spatial and visual properties to any node or model mesh within the scene. We conclude that the framework has been a success. We have completed what we have set out to develop and create, we have combined multiple data-sets to create improved terrain data-sets for further research and development. We have created a framework which combines the real-world data of Ordnance Survey, LiDAR, and OpenStreetMap, and implemented algorithms to create procedural assets of buildings, highways, terrain, amenities, model meshes, and boundaries. for visualisation, with implemented features which allows users to search and manipulate a city’s worth of data on a per-object basis, or user-defined combinations. The successful framework has been built by the cross domain specialism needed for such a project. We have combined the areas of; computer games technology, engine and framework development, procedural generation techniques and algorithms, use of real-world data-sets, geographical information system development, data-parsing, big-data algorithmic reduction techniques, and visualisation using shader techniques
How Far Is It? Of Geocaching and Emplacement in Athens, Greece
Geotechnologies are increasingly prominent, accessible, and interactive. Hand-held devices can localize one’s current geographic position with an unsettling precision. With the emergence of such mapping apparatuses, GPS-informed practices have proliferated. They redefine our engagement with space/place in ways that anthropologists need to attend to. Geocaching, a popular activity happening across the world, provides an ethnographic example of interest whose resonance extends beyond its practice.
This paper focuses on the ways in which spaces have the potential to become meaningful in specific ways for those engaging in this practice. I adopt an autobiographical approach, which I carefully unpack, following my movement in the context of geocaching in Athens to gain an embodied understanding of the place-making possibilities afforded by the activity. It is argued that emplacement –that is, a situated body-mind-environment relationship– can result from a particular form of sensory and affective engagement with and negotiation of a device-environmental dialectic.
To this end, I sketch a critique of geographic apparatuses such as maps, coordinates, and GPS devices, informed by the ironic double-bind geocachers must navigate. While they require geotechnologies to situate the approximate location of a geocache, they also risk being deceived by incongruence between reductive and life-annihilating “map spatialities” and “the realities on the ground” (in all their sensuous and affective possibilities). My work also demonstrates, in part, that geographic apparatuses may be thought of as cultural technologies, as are the processes and practices by which we use, evaluate, and ultimately translate them. It is through this experience of movement and sensory negotiation between technology and environment, I contend, that places can meaningful for geocachers in new and specific ways
Usability of Online Virtual Geographic Environment for Urban Design
Collaborative Virtual Geographic Environment (CVGE), a technology derived from Virtual Reality (VR), is today becoming widely and freely available. This technology has potential for use in the field of 3D urban planning and design. An example is the online tool OpenSimulator. Rigorous assessment of the usability of such tools is needed to determine their impact on the field of urban design. A previous study consulted with a small group of urban design professionals and concluded from a user satisfaction and usability standpoint that online VR had potential value as a 3D collaboration, remote communication and marketing tool. However, visual quality and geographic accuracy of the technology are downsides that need to be overcome. This research takes the investigation a step further than the previous study to also examine the usability aspects of efficiency (how quickly tasks are completed) and effectiveness (how successfully tasks are completed), relating to CVGE used in the design process. The comparative study tests a CVGE (with increased graphic fidelity and geographic content to address the feedback of the previous study) of a subdivision design in a suburb of Dunedin, New Zealand, against 3D models built with a Geographic Information System (GIS – ArcGIS) and Computer Aided Design (CAD – BricsCAD) tools, two types of software that are already widely adopted and well established in urban design professional practice. This research collected and analysed the experiences and results from 16 urban design professionals and students who attempted to perform timed tasks correctly in each of the environments, before being asked questions about the technologies involved and the importance they perceive the technologies to have to their professional work. The results support and reinforce the feedback for VR from the previous study, with the graphical and geographic data issues being somewhat addressed and a number of new issues identified which also require further refinement of the technology to suit the application. Ease-of-use, and the associated fastest speed of completion of tasks, were significant outcomes to emerge from the comparison with GIS and CAD, and the results point to the likely level of integration of CVGE technology in an urban planning and design context in the future
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